Knife grinder



July 7, 1956 B. B. STOCKARD, JR

KNIFE GRINDER Filed May 4, 1954 Wavy INVENTOR.

United States Patent KNIFE GRINDER Ben B. Stockard, Jr., Greensboro, N.C., assignor to Newman Machine Company, Inc., Greensboro, N. C., acorporation of North Carolina Application May 4, 1954, Serial No.427,552

3 Claims. (Cl. 51-92) The present invention relates to a knife grinderand more particularly to a machine for grinding cutterheads which have aplurality of cutting knives projecting from a holder.

It is conventional in the knife grinding art to have a reciprocatingwork table slide over a bed in which either accurately machined V-waysor dovetailed ways are provided to guide the moving elements. Byemploying V- ways between the bearing surfaces of the sliding members itis usually necessary that some means be provided to prevent table fromtilting or skewing upon knife engagement with the grinding wheel. tailedbearing surfaces or guide members on the bed ways tilt is usuallyeliminated. However, in each case heavy castings are usually used forthe table to provide a stable work rest thus requiring large bearingcontact surface areas between the bed and the sliding table that must beaccurately machined. Furthermore, due to the large bearing areas theforce necessary to slide the table relative to the bed is considerableand usually the use of a mechanism to improve the mechanical advantagetherebetween is required, such as, a crank lever with pinion and rack ora gear train system or other conventional devices to traverse the tableover the bed will prevent the operator from exercising complete controlover the depth of cut, the spark out period and also subjects the knifeto considerably more metal removal than is required.

Therefore it is an object of the present invention to provide a knifegrinder with a reciprocable table which will slide over a tablesupporting rail with a minimum bearing surface contact.

Another object of the present invention is to provide a cutterhead knifesharpener in which a work supporting table will overhang a rail memberand higher pairing means is provided between the table and rail so thata minimum bearing surface contact results as the table is reciprocated.

Still another object of the present invention is to provide a cutterheadknife conditioner in which a work table engages a supporting rail withhigher pairing means so that the length of the reciprocating stroke ofthe table will be equal to the linear reciprocation of the actuatingforce acting on the table.

A further object of the present invention is to provide a knife grinderwhich may be manually reciprocated linearly so that the operator maycontrol the depth of cut and the final spark out or finish cut on theknife.

Another object of the present invention is to provide a knife grinderwhich has a minimum of machined surfaces by using rollers to contactplane bearing surfaces.

Additional objects of the present invention are to provide a knifesharpener which may be operated with .a minimum of frictional bearingsurface contact, one that is simple to operate and economical tomanufacture.

Other objects and many of the attendant advantages of this inventionwill be readily appreciated as the same becomes better understood byreference to the following "ice 2 detailed description when consideredin conjunction with the accompanying drawings wherein:

Fig. l is an isometric View illustrating a knife grinder embodying thepresent invention;

Fig 2 is a slightly enlarged partial isometric View of the rail and thetable supported bearing roller elements associated therewith;

Fig. 3 is an enlarged partial section view of the overhanging work tablesupported on the rail member by the higher pairing means; and

Fig. 4 is an enlarged bottom plan view of a section of the tableindicating the roller suspension and a bearing surface wiping means.

Referring more particularly to the drawings wherein there is illustratedin Fig. l, a base plate 10 to which the bottom end of a column 11 isretained in a vertical position to support a saddle 12 securely clampedby suitable fastening means 13 to the top end of the column. A grindingattachment 14 is securely supported on the saddle 12 about the motordrive 15, and the motor drive has a shaft 16 that extends horizontallyto form an arbor With the use of dovefor receiving the grinding wheelflanges 17, only one being shown, a cup-shaped grinding wheel 18 on thearbor between the flanges 17, and a lock nut 19.

Intermediate the height of the vertical column 11 is a yoke 20 thatencircles the column 11 and extends laterally therefrom. The yoke 20 maybe releasably clamped in the desired vertical position by the clampingbolts 21. Rotary movement of the yoke 20 is prevented by the elongatedsquare key and rack 22 fastened to one side of the column 11. Extendingto each side of the column 11 on the yoke 20 is a pair of horizontalparallel openings 23 and 24 for frictionally retaining a pair of bracketsupporting arms 25 and 26 respectively therein. A rail supportingbracket 27 extending transversely across the arms 25 and 26 is held onone end of each arm.

In the illustrated embodiment as shown in Fig. 3, one side of thebracket 27 is provided with sleeves 28 for receiving therein one end ofthe arms 25 and 26 to which the sleeves are clamped by fastening means29. It is to be understood however, that individual sleeve flanges orbrackets on each arm may be used instead of a transverse bracket. Theother side of the bracket 27 has a vertical rail supporting surface 30in which a plurality of spaced holes 31 are provided. An elongated tablesupporting rail 32 having ground bearing surfaces 33 and 34 verticallyspaced from each other and on opposite sides of the rail, and ahorizontal bearing surface 35 on the top of the rail 32 is secured tothe bracket surface 30 by suitable fastening means which will engagewith the holes 31. The rail bearing surfaces 33, 34 and 35 may be eithernarrow ground or machined bands extending the length of the rail or theentire surface of each side of the rail may be ground or machineddepending upon the contact to be made by the higher pairing means to beemployed in cooperation with the surfaces and to be describedhereinafter. End stops 35 and 36 which may be made adjustable accordingto the length of the table stroke will engage with suitable projections37 and 38, respectively, on the work supporting table 39 to limit thethrow of the table during table reciprocation.

For the purpose of this specification the terminology higher pairingshall mean that contact between links will be either of line or pointcontact as distinguished from lowering pairing which exists when contactbe tween elements is plane surface contact.

In Figs. 1 and 3 there is shown an overhanging suspended work supportingtable 39 that has a horizontal plane work surface 40 on which a clampingbracket 41 may be secured by fastening means 42 which extends into thetable 39. The bracket 41 may be positioned on the work supporting table39 so that a cutterhead 43 may be positioned adjacent the grinding wheel18. A downwardly, angularly disposed, depending member 44 extends fromthe bottom of the table 39 to a position adjacent the bearing surface 34on the rail 32. The table 39 is suspended from the rail 32 by higherpairing means mounted on the table 39 at suitable positions.

In the illustrated embodiment pairs of freely rotatable rollers 45, 46and the single roller 47 are mounted on shafts '48, 49, and 56respectively which shafts are retained in and project from the table 39and depending member 44. Rollers 45 are mounted to roll on the 'horizontally spaced vertical rail bearing surface 33. Rollers 46 are mountedto rotate about the horizontally spaced shafts 49 which are retained ina position intermediate the table width and each roller 46 will roll onthe top horizontal rail bearing surface 35 to support the vertical loadon the table 39. Roller 47 is supported for free rotation about thehorizontally spaced vertical shaft '50 at the end of the dependingmember 44 and the roller 47 will roll on the 'bottom vertical railbearing surface 34. Rollers 45 and 47 acting on the rail bearingsurfaces 33 and 34, respectively, will resist the turning couple momentthat acts on the overhanging table 39.

It is Within the contemplation of this invention that the rotatableroller elements may be replaced by other elements to produce higherpairing whether with straight line or point contact, for example, diskwheels, roller bearings, or rotatable ball members may be used. Inaddition it is within the scope of this invention that the rail 32 maybe disposed at other angles than that illustrated and the table 39 maybe supported by higher pairing means as required by the disposition ofthe table.

Reciprocation of the table 39 may be effected manually by :linearreciprocation of the handle 51 attached to the table 39 at anappropriate position within convenient reach of the operator.

A conventional horizontal traversing mechanism 52 is keyed to thebracket 27 to position the work table 39 in the desired horizontalposition relative to the grinding wheel 18. The vertical adjustingmechanism 53 is provided with a worm and worm gear (not shown) whichworm gear will engage with the vertical key and rack 22 to locate thetable 39 in the desired vertical position relative to the grinding Wheel18.

In order to remove grit or other deleterious matter that may adhere tothe bearing surfaces 33, 34 and 35 there may be provided adjacent eachof the rollers and contiguous with the fiat bearing surfaces 33, 34 and35, 'suitable wiping pads 54 that are supported from the table 39 towipe the critical surfaces. The pads 54 may be felt or otherconventional wiping material suitable for removing foreign matter thatmay cling to the flat surfaces on the rail 32. Additional wiping padsmay be supported from the table in direct contact with the rollers 45,46 and-47.

In operation, the cutterhead 43 normally having a plurality 'of "knivesmounted thereon is clamped on the bracket 4-1 with one knife 55 exposedat the desired angle to the grinding wheel 18. By adjusting thehorizontal traversing mechanism 52 and the vertical traversing mechanism'53 the exposed knife is oriented to the initial cutting position. Theyby linearly reciprocating the handle 51 the table will be reciprocatedwith a linear stroke of the same length as the length of the linearstroke applied to the handle. It will be readily apparent that a minimumof effort is required to shift the table in either direction. Thus whenthe handle 51 is manually reciprocated'the operator may effectivelycontrol the depth of each cutting increment as well as the spark outperiod.

Although the invention has been described with specific reference to aparticular embodiment thereof, it is to be understood that it is not tobe so limited, since changes in the parts, such as mechanicalequivalents, and in their relative arrangement can be made therein whichare Within the full intended scope of this invention as defined by theappended claims.

I claim:

1. A cutterhead grinder comprising a base, a vertical column mounted insaid base, a saddle mounted on the column, a grinding attachment havinga grinding Wheel and means to drive said grinding wheel supported on thesaddle, a yoke encircling said column intermediate the base and thesaddle, said yoke having a pair of transverse horizontal openingstherein extending on each side of the column, means for releasablylocking the yoke in a selected position, a rail supporting brackethaving a pair of extending arms in said yoke openings, a rail membermounted to the bracket, said rail having a plurality of exposed bearingsurfaces, two of said bearing surfaces being vertically disposed, andspaced apart on opposite sides of the rail and a top horizontal bearingsurface, means for moving the bracket and rail horizontally, means formoving the. supporting bracket and rail vertically, a Work supportingtable having a plurality of rollers mounted for free rotation on thetable, each of the rollers engaging with one of the bearing surfaces onthe rail to suspend the working table in a horizontal position, meansadjacent the rollers to wipe the bearing surfaces and the rollers, saidtable being in juxtaposition with said grinding wheel, stops on saidrail to limit the length of table stroke, and a manuallyoperable handlefixed to the table whereby the length of reciprocating stroke of thetable will be equal to the linear reciprocating stroke of the handle.

2. A cutterhead grinder comprising a base, a vertical column mounted insaid base, a saddle mounted on the column, a grinding attachment havinga grinding wheel and means to drive said grinding wheel supported on thesaddle, a yoke encircling said column intermediate the base and thesaddle, said yoke having a pair of transverse horizontal openingstherein extending on each side of the column, 'means for releasablylocking the yoke in a selected position, a rail supporting brackethaving a pair of extending arms in said yoke openings, a rail membermounted to the bracket, said rail having a plurality of exposed bearingsurfaces, two of said bearing surfaces being vertically disposed, andspaced apart on opposite sides of the rail and a top horizontal bearingsurface, meansforimoving the bracket and rail horizontally, means formoving the supporting bracket and rail vertically, a work supportingtable having a plurality of rollers mounted for free rotation on thetable, each of the rollers engaging with one of the bearing surfaces onthe rail to suspend the working table in a horizontal position, saidtable being in juxtaposition with said grinding wheel, and a manuallyoperable handle fixed to the table whereby the length :of reciprocatingstroke of the table will b equal to the linear reciprocating stroke ofthe handle.

3. cutterhead grinder comprising a base, a vertical column mounted insaid base, a saddle mounted on the column, a grinder attachment having agrinding wheel an'd'm'eans to drive said grinding wheel supported on thesaddle, a yoke encircling said column intermediate the base and thesaddle, said yoke having a pair of openings therein extending on eachside of the column, means for releasably locking the yoke in a selectedposition, a rail supporting bracket having a pair of extending arms insaid yoke openings, a rail member mounted on the bracket, :sai'd railhaving a plurality of plane bearing surfaces, two of 'said surfacesbeing on opposite sides of the rail to resist a turning couple moment,and a third surface being on-the edge of the rail to support a verticalload thereon, means for moving said bracket and rail horizontally, meansfor moving said bracket and rail vertically, a work supporting tableoverhanging said rail, higher pairing means interposed between said railand table, limit stops selectively spaced on the rail to limit tablestroke, said table being in juxtaposition with said grinding wheel, anda manually operable .handle fixed fQth'e table whereby the length of thereciprocating stroke of the table will be equal to the linearreciprocating 671,256 stroke of the handle. 680,345 932,791 ReferencesCited in the file of this patent 1,043,948 5 1,863,036 UNITED STATESPATENTS 2,489,453

184,933 Vogeley Nov. 28, 1876 248,744 Holmes Oct. 25, 1881 439,154 HolzOct. 28, 1890 965,080

6 Whitney Apr. 2, 1901 Morrison Aug. 13, 1901 Le Blond Aug. 31, 1909Mandley Nov. 12, 1912 Wicke June 14, 1932 Fouquet Nov. 29, 1949 FOREIGNPATENTS France Feb. 8, 1950

